<!--
  speedy-vision.js
  GPU-accelerated Computer Vision for JavaScript
  Copyright 2020-2024 Alexandre Martins <alemartf(at)gmail.com>

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

  normalize-demo.html
  Image normalization demo
-->
<!doctype html>
<html>
    <head>
        <meta charset="utf-8">
        <meta name="description" content="speedy-vision.js: GPU-accelerated Computer Vision for JavaScript">
        <meta name="author" content="Alexandre Martins">
        <title>Normalize camera stream</title>
        <link href="demo-base.css" rel="stylesheet">
        <script src="demo-base.js"></script>
        <script src="../dist/speedy-vision.js"></script>
    </head>
    <body>
        <h1>Normalize camera stream</h1>
        <form autocomplete="off">
            <div>
                Map pixels to range:
                &nbsp;&nbsp;
            </div>
            <div>
                <label for="min-value">min</label>
                <input type="range" id="min-value" min="0" max="255" value="0" step="1">
            </div>
            <div>
                <label for="max-value">max</label>
                <input type="range" id="max-value" min="0" max="255" value="255" step="1">
            </div>
        </form>
        <div>
            <span id="status"></span>
            <canvas id="canvas-demo"></canvas>
        </div>
        <script>
window.onload = async function()
{
    /*

    Our pipeline:

    Image ---> Convert to ---> Normalize ---> Image
    Source     greyscale       image          Sink
               |
               |
               +-------------> Image
                               Sink

    */

    // get camera stream
    const camera = await Speedy.camera();

    // setup the pipeline
    const pipeline = Speedy.Pipeline();
    const source = Speedy.Image.Source();
    const sink1 = Speedy.Image.Sink('grey');
    const sink2 = Speedy.Image.Sink('norm');
    const greyscale = Speedy.Filter.Greyscale();
    const normalize = Speedy.Filter.Normalize();

    source.output().connectTo(greyscale.input());
    greyscale.output().connectTo(normalize.input());
    greyscale.output().connectTo(sink1.input());
    normalize.output().connectTo(sink2.input());
    pipeline.init(source, sink1, sink2, greyscale, normalize);

    source.media = camera;
    normalize.minValue = 0;
    normalize.maxValue = 255;

    // Main loop
    (function() {
        let grey = null, norm = null, frameReady = false;
        const canvas = setupCanvas('canvas-demo', camera.width, camera.height * 2);

        async function update()
        {
            const result = await pipeline.run();
            grey = result.grey;
            norm = result.norm;

            frameReady = true;
            setTimeout(update, 1000 / 60);
        }
        update();

        function render()
        {
            if(frameReady) {
                renderMedia(norm, canvas);
                renderMedia(grey, canvas, 0, norm.height);
            }

            frameReady = false;
            requestAnimationFrame(render);
        }
        render();

        setInterval(renderStatus, 200);
    })();

    // setup sliders
    const minSlider = document.getElementById('min-value');
    const maxSlider = document.getElementById('max-value');
    minSlider.oninput = () => normalize.minValue = minSlider.value;
    maxSlider.oninput = () => normalize.maxValue = maxSlider.value;
}
        </script>
        <section id="speedy-vision">
            <span>Powered by <a href="https://github.com/alemart/speedy-vision" target="_blank">speedy-vision.js</a></span>
            <a href="https://github.com/sponsors/alemart" target="_blank" class="button">
                <img alt="GitHub Sponsors" src="https://img.shields.io/github/sponsors/alemart?style=for-the-badge&logo=github&label=Sponsor&labelColor=royalblue&color=gold">
            </a>
        </section>
    </body>
</html>